Synthesis of magnetic biochar for utilization in Fenton based - PowerPoint PPT Presentation

Synthesis of magnetic biochar for utilization in Fenton based process Gozde Duman T ac, Jale Yanik Ege University, Faculty of Science, Chemistry Department,Izmir/ TURKEY

Dye wastewater treatment • Used in the textile, cosmetic, pharmaceutical and food industries • High volumes of wastewater during operation • Complex structure, resistant to biodegradation Coagulatio n Membrane Adsorption separation Dye wastewat er treatmen t O 3 Fenton Reaction oxidation

Advanced Oxidation Process  Based on chemical oxidation by forming very reactive species such as hydroxyl radicals (·OH)  Degrades organic pollutants completely to harmless chemicals, mainly CO 2 and H 2 O  Feasible option for biologically persistent wastewater  Widely recognized as highly effjcient treatments for recalcitrant wastewater

Fenton Process • The chemical oxidation of organic compounds by H 2 O 2 using Fe ions as a catalyst Particularly attractive because of • the low costs • the lack of toxicity of the reagents • the simplicity of the technology

Fenton Process Disadvantages of homogeneous catalysis  50–80ppm of ions needed in solution • above environmental regulations to dump directly into the environment => [Fe]max =2 ppm • the removal/treatment of the sludge-containing metal ions at the end of treatment  Not recyclable Pure Metal oxides; poor stability, inert activity, etc. Heterogeneous catalyst Fe 3+ +OH - +HO H 2 O 2 Fe 2+ Dis s olution H + +HO 2 /O 2 Fe 3+ Fe 3+(a Fe C a ta ly s t 3+ q) H 2 O 2 H 2 O 2 Fe 2+ +H + +HO Fe 2+ 2 Dis s olution Fe 2+(a q) Fe +OH - +HO 3+ H 2 O 2

Biochar Pyrolysis Biochar for wastewater treatment Biomass Biochar -Adsorbent - support for oxidation catalyst Modifjcation/activation Hydrothermal Carbonization Increase surface area OR Surface functional group COOH HO OH O - Biochar M Loading metal species M M M

PURPOSE Decolorization of wastewater containing methylene blue via Fenton process in presence of Fe doped biochar Fe doped biocha r  Synthesis and characterization of Fe loaded biochars  Catalyst screening  Parametric study on Methylene blue removal

ANAL YSIS termination of Methylene blue (MB) removal  Performed by measuring the absorbance of the methylene blue concentration at the maximum absorbance wavelength of each compound in a UV/VIS Spectrophotometer ( Varian Cary 100 Bio)  The wavelengths λ =664 nm for MB,  Removal effjciency (de-colorization) was calculated by MB Removal where m 0 and m f were initial and fjnal concentration of MB

MATERIALS AND METHODS Biomass: T wo phase olive mill waste(TP) Properties of TPOMW, % Moisture 66.4 Proximate analysis, wt % (db) Ash 3.8 TPOMW Volatile 68.5 matter Fe source : Fixed carbon 27.7 -FeSO 4 (Fe), Ultimate analysis, wt % (db) C 51.47 -Red Mud (RM): Fe rich ( containing H 7.02 38% Fe 2 O 3 ) waste sludge from N 1.09 aluminum company S 0.13 O 36.51 -Acidifjed Red Mud (ARM): Dissolved in 10 % HCl solution

MATERIALS AND METHODS Process Yield**, % TP dry + Fe source in solution P-Fe-500* Pyrolysis 60.2 P-Fe-700* Pyrolysis 55.7 HTC-Fe HTC 49.6 P-RM-500* Pyrolysis 68.9 P-RM-700* Pyrolysis 57.2 HTC-RM HTC 81.7 P-ARM-500* Pyrolysis 72.0 Thermocouple Impregnation in oven Pressure gauge P-ARM-700* Pyrolysis 61.3 at 110 o C overnight Needle valve Oven Stirrer Water Thermocouple *Magnetic properties* Volatiles N 2 Hydrothermal carbonization (HTC) Oven at 220 o C for 1 hour Pyrolysis at 500 and 700 o C for 1 hour Filtrated,washed and dried in oven at 110 o C overnight **based on initial biomass amount

MATERIALS AND METHODS Fenton Reaction Experiments Batch experiments  250 ml erlenmayer fmask  150 rpm shaking Tested parameters  Catalyst type  Day light and under dark  Concentration of H 2 O 2  pH  MB concentration

RESUL TS -Comparison of Fe source P-Fe-500 P-Fe-700 100 90  RM based biochars had low 80 activity. MB Removal ( %) 70  The use of ARM instead of 60 50 RM improved the removal 40 of MB. 30  Pyrolysis temperature for 20 Fe based biochars had 10 0 signifjcant efgect. 0 1 2 3 4 5 Time (hour) Conditions: 100 ppm MB, 10 mM H 2 O 2 , daylight, 150 rpm shaker, pH was adjusted to 3

RESUL TS- FeSO 4 based catalyst Day light P-Fe-700 P-Fe-500 HTC-Fe P-Fe-700 100 100 MB removal (%) 80 80 MB removal, % 20 hours !!! 60 60 40 40 20 20 0 0 0 0.5 1 2 3 4 5 7 16 20 0 0,5 1 1,5 2 2,5 3 3,5 Reaction Time (h) Reaction Time (h) Under Dark P-Fe-700 P-Fe-500 HTC-Fe Fe content of effmuent 100 MB removal (%) water, ppb 80 P-Fe-500 128 60 P-Fe-700 4 40 HTC-Fe 357 20 0 0 1 2 3 4 5 Reaction Time (h)

RESUL TS- Cyclic usage of catalyst Fenton oxidation with P-Fe-500 P-Fe-500 HTC-Fe Before After 100 90 80 70 MB removal, % 60 50 40 30 20 10 0 1st 2nd 3rd 4th 5th Cycle  No activity losses in case of P-Fe-500 after 5 cycle. Conditions: 50 ppm MB, 10 mM H 2 O 2 , daylight, 150 rpm shaker, no pH adjustment ( ~3.5)

RESUL TS- FeSO 4 based catalyst Inorganic content, % SEM images P-Fe-500 P-Fe-500 P-Fe-700 HTC-Fe Fe 22.02 25.86 1.35 Al 0.06 0.07 0.07 HTC-Fe Si - 0.02 0.03 Mg 0.09 0.11 - Na 0.29 0.32 0.12 Ca 0.27 0.32 0.09 K 3.22 4.01 0.11 P-Fe-700 Iron  Loading of Fe failed by particles hydrothermal carbonization

RESUL TS- FeSO 4 based catalyst FTIR spectrum XRD pattern ✮ ✮ ✮ ✮ ▲ ✮Fe 3 O 4 ▲Fe 2 O 3 P-Fe-500 HTC-Fe Aromatic C=C ity s n Aliphatic C-O-C te -OH In P-Fe- Aliphatic -CH 3 500 Carboxylic C=O 5 15 25 35 45 55 65 75 85 2 Theta 3650 3150 2650 2150 1650 1150 650 HTC-Fe Wavenumber (cm-1) Intensity 5 15 25 35 45 55 65 75 85 2 Theta

RESUL TS- Parametric study MB concentration: 50, 100, 150 and 200 ppm Catalyst : P-Fe-500 50 ppm 100 ppm 150 ppm 200 ppm 100 90 80 70 MB Removal, % 60 50 40 30 Concentration 20 Removal 10 0 0 1 2 3 4 5 6 7 Reaction time (h) Conditions: 10 mM H 2 O 2 , daylight, 150 rpm shaker, no pH adjustment ( ~3.5)

RESUL TS- Parametric study Initial H 2 O 2 concentration: 2.5, 5, 10 and 15 m M Catalyst : P-Fe-500 2.5 mM 5 mM 10 mM 15 100 90 80 70 MB Removal( %) 60 50 40 30 20 Lower H 2 O 2 concentration longer 10 reaction time 0 0 1 2 3 4 5 6 7 Reaction time (h) Conditions: 50 ppm MB, daylight, 150 rpm shaker, no pH adjustment ( ~3.5)

RESUL TS- Parametric study pH: 2.5, 3.6 (natural pH of MB), 7 and 9 Catalyst : P-Fe-500 2.6 3.8 7 9 100 90 Low pH increases solubility of Fe 80 ions 70 MB Removal, % 60 50 40 30 20 After 24 h removal was not 10 completed!! 0 0 1 2 3 4 5 6 7 Reaction time (h) Conditions: 50 ppm MB, 10mM H 2 O 2 concentration, daylight, 150 rpm shaker,

Conclusion -Fenton oxidation of MB was achieved with the catalysts prepared by TP . -Release of Fe faciliates degradation of MB. -P-Fe-500 had the highest activity stability in 5 cycles. Fe concentration in effmuent water is acceptable for direct dumping. -pH is most efgective parameter, which afgect the solubility of Fe in wastewater. -Biochars obtained by pyrolysis showed magnetic properties whereas magnetic biochar could not produced by HTC. -Biochar obtained from pyrolysis at lower temperature showed higher  Ongoing studies focus on red mud to produce efgective and stable activity than that at higher temperatures. catalyst, independent from difgerent pH.  In future work, difgerent pollutants can be tested in their natural pH.

THANK YOU FOR LISTENING… Special Thanks… • PhD candidate Gulen T ekin • Dr. Dogan T ac • Dr. Raif Ilkac • Berkay Leskeri